Assembling and disassembling energy storage devices, such as pressurized fluid accumulators, spring-loaded pistons and the like, can be a potentially hazardous operation. Normally, a plurality of fasteners loadably secure a cover or end plate against a housing to thus contain the potential energy stored within the housing. During the installation or removal of the cover, however, the fasteners are not always uncoupled in proper sequence or to the proper degree with the result that the stored energy tends to transversely cock the cover relative to a central longitudinal axis of the storage device and to thereby excessively load one or more of the fasteners causing them to fail. Such unlimited cocking of the cover can then result in a catastrophic sequential failure of the remaining fasteners until they and the cover are propelled outwardly from the housing as missiles with such a force as to create a serious hazard to any person or other object in their path.